Detecting multi-way epistasis in family-based association studies

Area of Science:

• Genetics
• Biostatistics
• Computational Biology

Background:

• Genome-wide association studies (GWAS) have identified numerous disease-associated genetic variants.
• Understanding gene-gene interactions (epistasis) is crucial for a comprehensive view of disease genetic architecture.
• Family-based study designs are valuable for investigating genetic interactions.

Purpose of the Study:

• Introduce M-TDT (multi-locus transmission disequilibrium test) for detecting family-based multi-locus effects.
• Compare M-TDT performance with multifactor dimensionality reduction pedigree disequilibrium test (MDR-PDT).
• Evaluate M-TDT for hypothesis-driven investigation of complex disease etiology.

Main Methods:

• Extended the transmission disequilibrium test (TDT) to a multi-locus framework (M-TDT).
• Developed tests for comparing additive and epistatic models, handling marker non-independence, and multiple offspring.
• Simulated data for three independent biallelic loci to assess performance.

Main Results:

• M-TDT successfully identified joint-locus effects and differentiated between additive and epistatic models.
• Demonstrated M-TDT's utility with a practical example involving malaria susceptibility genes.
• M-TDT proved effective in a hypothesis-driven context for testing multi-way epistasis.

Conclusions:

• M-TDT is valuable for hypothesis-driven research on multi-way epistasis in common diseases.
• MDR-PDT is more suitable for hypothesis-free, genome-wide investigations in family settings.
• M-TDT enhances the understanding of complex genetic architectures underlying diseases.